1. Field of the Invention
The present invention relates in general to a temperature sensor and a method for providing a condition representative of the profile of the thermal gradient of an object, and more specifically resides in the utilization of a poled, pyroelectric layer as a temperature sensitive element of such a sensor.
2. Description of the Prior Art
It is well known that temperature differentials over the exterior surface area of an object may indicate an existing or developing malfunction. For example, a defect in a motor may be evidenced by abnormal localized heating of the motor housing in the vicinity of the defect. Also, carcinogenic tissue in a human body is evidenced by a higher temperature than normal healthy tissue. One prior art sensor for detecting such temperature variations and for providing a temperature pattern thereof is disclosed in a U.S. Pat. No. to Fergason et al, 3,114,836. The Fergason et al sensor employs the use of a liquid crystal temperature sensitive material that selectively scatters light rays to present a color indication of the thermal profile of an object with which it is in contact. However, the profile provided is not a remanent profile and upon removal of the Fergason et al sensor from contact with the object the color of the sensor will disappear as the sensor returns to the ambient temperature.